Pigment dispersions and their use for the pigmenting of hydrophilic and hydrophobic media

Abstract

Stable dispersions of pigments are obtained by finely distributing inorganic and/or organic pigments in water and/or agents preventing or retarding the drying-up of the dispersions containing condensation products of aromatic hydroxy compounds and alkanals as well as surfactants, said condensation products and surfactants containing aliphatic carbon chains of more than 5 carbon atoms. The dispersions are compatible with hydrophilic and hydrophobic media.

What is claimed is: 
     
       1. A pigment dispersion comprising (a) a tinctorially effective amount of an organic and/or inorganic pigment,   (b) water and/or a water-miscible compound as a dispersion medium for said pigment,   (c) a condensation product of an aromatic hydroxy compound and an alkanol,   (d) a surfactant containing an aliphatic carbon chain of more than 5 carbon atoms, said condensation product and surfactant being present in amounts effective to disperse said pigment in said dispersion medium, said condensation product having an average molecular weight of 400 to 5000 and consisting of recurring units of the formula ##STR2##  wherein Ar is benzene or naphthalene; X is hydroxy, etherified or esterified hydroxy; Y is hydrogen, --R 4 , --OR 4 , halogen, --CO--R 4 , --COOR 4 , --CONR 4  R 5  or --NR 4  COR 5 , R 4  and R 5  standing, independently of each other, for hydrogen and alkyl of 1 to 4 carbon atoms; R 1 , R 2  and R 3  are, independently of each other, hydrogen, alkyl, alkenyl or alkapolyenyl each having up to 30 carbon atoms, the carbon chains of which are uninterrupted or interrupted by --O--, --S--, --NR 4  --, --CO--, --COO--, --CONR 4  -- or phenylene, and which are unsubstituted or substituted by halogen, hydroxy or carboxy; with the proviso that per each two such recurring units at least one of R 1 , R 2  and R 3  contains an aliphatic chain of more than 5 carbon atoms.   
     
     
       2. A pigment dispersion as claimed in claim 1, which contains a preservative and/or a foam-reducing substance. 
     
     
       3. A pigment dispersion as claimed in claim 1, which contains a condensation product of an aromatic hydroxy compound and an alkanal deriving from an alkylphenol with an alkyl radical of more than 5 carbon atoms and formaldehyde. 
     
     
       4. A pigment dispersion as claimed in claim 1, which contains a condensation product of an aromatic hydroxy compound and an alkanal deriving from a phenol or a naphthol and an alkanal of more than 5 carbon atoms. 
     
     
       5. A pigment dispersion as claimed in claim 1, which contains as a surfactant a non-ionic surfactant. 
     
     
       6. A pigment dispersion as claimed in claim 5, which contains as a non-ionic surfactant an addition product of 5 to 20 mols of ethylene oxide onto an alkylphenol and/or a fatty alcohol. 
     
     
       7. A pigment dispersion as claimed in claim 1, which contains as a surfactant an anionic surfactant. 
     
     
       8. A pigment dispersion as claimed in claim 7, which contains as an anionic surfactant an alkyl sulfate, alkyl sulfonate and/or alkyl-benzene sulfonate. 
     
     
       9. A pigment dispersion as claimed in claim 1, which contains as a surfactant a mixture of an anionic and a non-ionic surfactant. 
     
     
       10. A pigment dispersion as claimed in claim 1, which contains a polyhydric alcohol and/or an acid amide as a compound that is miscible with water and prevents or retards the drying-up. 
     
     
       11. A pigment dispersion as claimed in claim 1, containing 5 to 80% by weight of pigment, 0.1 to 7% by weight of said condensation product,   3 to 30% by weight of said surfactant and   20 to 90% by weight of water and/or said water miscible compound.   
     
     
       12. A pigment dispersion as claimed in claim 11, containing 0.3 to 3% by weight of condensation product. 
     
     
       13. A pigment dispersion as claimed in claim 11, containing 5 to 20% by weight of surfactant. 
     
     
       14. A process for pigmenting hydrophilic or hydrophobic media which comprises incorporating into said media a pigment dispersion as claimed in claim 1.